(1) Field of the Invention
This invention relates to cereal preparation and more particularly to preparing a product commonly called masa.
(2) Description of the Prior Art
Masa is a term used to refer to a cereal product in the United States. In Mexico it is commonly a corn product also known as mensa.
On a commercial basis, the cereal which is used for making masa at the present time is corn. However, the process according to this application also has application for milo, wheat, oats, barley, triticale, rye, and rice.
Traditionally and before this invention, the product was made by a process which included cooking for a period of approximately 18 minutes and steeping for 8 to 10 hours, kernel corn in a lime (calcium hydroxide) solution. Thereafter, the husk of each kernel was, having been loosened by the steeping, removed, the kernel ground into a meal and used; or was dried for flour. Obviously, the steeping period removed a large amount of vitamins, starches, oils and other nutrients contained in the corn. The losses are often from 20% to 40% by weight.
My prior U.S. Pat. Nos. 4,234,614, issued on Nov. 18, 1980, and 4,126,707, issued on Nov. 21, 1978, describe a method for processing cereal grains which is summarized as including the steps of mixing cleaned kernels with water to form a thick slurry, pumping the slurry through a plurality of stages of pumps equipped with throttle valves to remove the husk from the kernels, dewatering the slurry to remove excess waters, surface drying and aspirating to separate the husks from the kernels. The grains may then be milled, preferably by an impact grinder.
The prior patents also disclose a method of removing any remaining husk and the germ which includes cracking the grain in a fan, then feeding the sized grits and husks from the cracked grain to aspirators that separated the grits and husks. The germ may be removed by gravity separators.
Also, before this invention, Chardo W. Pierce obtained U.S. Pat. Nos. 3,694,220; 3,701,670; and 4,153,733. These patents disclose processing of grains by infrared radiation of the grains to partially gelatinize the grain to a soft, turgid state almost to the point of eversion. After radiation, the grains are immediately rolled to flake out them.